The effects of bilingualism on stuttering during late childhood

Peter Howell ^1*, Stephen Roger Davis ¹ and Roberta Williams ²

¹ University College London, United Kingdom
² City University, United Kingdom

^* To whom correspondence should be addressed. E-mail: p.howell{at}ucl.ac.uk.

Accepted 24 June 2008

Abstract

Objectives: To document distinct patterns of language use by bilingual children (use of an alternative language exclusively, LE, or along with English, BIL). To establish how these patterns affect onset of stuttering, school performance and recovery rate relative to monolingual speakers who stutter (MONO).

Design: Clinical referral sample with cases classified by speech-language therapists. Supplementary data obtained from speech recordings, interviews with child and family.

Setting: South-East England, 1999-2007. Participants Children aged 8-12 plus who stuttered (monolingual and bilingual) and fluent bilingual controls (FB).

Main outcome measures: Participants' stuttering history, SATS scores, measures of recovery or persistence of stuttering.

Results: The sample of 317 children had 69 bilinguals (prevalence rate of bilingualism in the stuttering sample was 21.8%). 38 children used a language other than English primarily or exclusively in the home and 36 of these (94.7%) bilinguals who stuttered did so in both their languages. There were fewer LE than BIL stuttering children at time of first referral to clinic (of the bilinguals who stuttered, 15/38, 39.5%, were LE and 23/38, 60.5%, were BIL). The reverse was the case in the fluent control sample (of the bilinguals who did not stutter, 28/38, 73.7%, were LE and 10/38, 26.3%, were BIL). The association between stuttering and bilingual group (LE/BIL) was significant by 2 and this is consistent with a higher chance of stuttering for BIL than LE speakers. For speakers who stuttered, age of stuttering onset for LE and BIL was similar to that reported for MONO groups (4 years 9 months, 4 years 10 months and 4 years 3 months for LE, BIL, MONO respectively) and males were affected in each of these groups to about the same extent (the male/female ratio was 4.1:1, 4.75:1 and 4.43:1 for LE, BIL and MONO respectively). For the 29 children who were old enough to complete the assessments, educational achievement at key stages one and two was not affected by either form of bilingualism relative to the MONO and fluent bilingual groups. For these same children, recovery rate for LE and MONO controls was significantly higher by 2 than for those who were BIL since birth (recovery rate for LE and MONO together was 55%, and for BIL was 25%).

Conclusions: There was an increased chance of stuttering onset for BIL children. The chances of recovery from stuttering were lower for BIL speakers than for LE and MONO speakers.